| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface acoustic wave device and a communication system solving a problem of an input/output impedance difference, and a new structure of communication equipment using the same. SOLUTION: An electomechanical coupling coefficient of an interdigital electrode 2 having a smaller number of electrode pairs of input/output interdigital transducers is set larger than an electromechanical coupling coefficient of an opposite interdigital electrode. An interdigital transducer 3 having a larger number of electrode pairs is divided into tracks in a direction perpendicular to the propagation direction of a surface acoustic wave, and each divided interdigital transducer group is electrically connected in series. Each intersection portion of the interdigital transducers is also connected in series. With this, it becomes possible to improve the performance of the surface acoustic wave device of a matched filter type, and the performance of the spread spectrum communication equipment of code spread system. COPYRIGHT: (C)2004,JPO
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